Track for distribution of electricity



0 United States Patent n113,546,367

[72] Inventors Derek James Hart; [56] References Cited Robert DavisLondon, land UNITED STATES PATENTS [21] P 827656 2,076,558 4 1937Hartman etal. 339/2I(S)UX [22] Wed May 3 081 442 3/1963 Platz 339/2IX[45] Paemed Dec-831970 3295093 i2/l966 Neul'il l l ll l e l iil 339/21[73] Assignee British Lighting Industries Limited London, EnglandPrimary Examiner-Laramie E. Askin [32] Priority July 22, 1968Attorney.loseph C. Ryan [33] Great Britain (3 I] No. 34943/68 [54] TRACKFOR DISTRIBUTION OF ELECTRICITY Cmms 1 Draw ABSTRACT: An electricitydistribution track suitable for [52] U.S. Cl. 174/99, overhead use has asubstantially U-shaped cross section and 191/23, 339/21, 339/22 hasledges upon which electrical connecters and outlet adap- [51] Int. ClH02g 5/04, ters can be slidably positioned, the track body havinglongitu- B60m l/34 dinally extending conducting strips mounted thereinwhich are [50] Field of Search 174/40, accessible from the interior ofthe track by way of slots, the

68(B), 70.3, 70(8), 99(8); 339/20, 21, 21(5), 22, 22(8), 22(T); l9l/22,23, 23(A), 24, 25, 45, 45(A); 104/108 slots effectively shielding theconducting strips from being inadvertently touched thereby preventingpersonnel receiving shocks therefrom.

a; IIIIIIII S PATENTED BED-8 19m 3546- 367 DEREK JAMES HART ROBERT DAVISC. ATTORNEY TRACK FOR DISTRIBUTION OF ELECTRICITY The presentinventionrelates to a track for the distribution of electricity and issuitable for use, inter alia, in factories and workshops where a commonsupply is required to which electrical components can be connected wheredesired.

The track can be centrally located, conveniently positioned overhead. Inone known system, a group of electric cables is carried, for exampleoverhead, by a trunking, and cables are withdrawn from the trunkingwhere a lamp or power tool is to be located. Such trunking isadditionally adapted to support lamps. A disadvantage of this system isthat tools are necessary to bare the cables and make the desiredconnections. This is a time consuming process. Furthermore,repositioning of the lamps or tools relative to the trunking will oftenrequire making new connections. v 6

According to the present invention, there is provided a track fordistribution of electricity comprising an elongate member having a baseand sides extending from the longitudinal edges of the base, and a pairof conducting strips which aremounted on or in the inner surfaces of thetwo sides in longitudinally extending channels, slots being associatedwith the channels to provide access .to the strips from the centralregion of the elongate member, the sides additionally being providedwith projections on which accessory members can be slidably mounted.

The track enables a plurality of components to be readily secured andelectrically connected to the track without the use of tools, by meansof accessory electrical connectors. The track is so designed thatrepositioning of the components relative to the track is facilitated bysliding the accessory connectors along the track. It is thus unnecessaryto remove the accessory connectors from the track. Furthermore,conventional connections of the components to cables carried by thetrack is eliminated.

The track includes a pair of conductor strips to which access isprovided from the. central region of the track through the slots. Theslots are so arranged that the conductor strips cannot be touchedaccidentally, thus preventing the possibility of shocks. A furthersafety feature is the provision of an earthing strip. The track furtherincludes grooves which are provided so that it can be secured to asurface such as a ceiling by means of a mating mounting track andT-bolts. However it will be appreciated that the track could be directlysecured to the surface by means such as screwing or bolting through thebase of the track into the said surface.

The elongate member is preferably made from an extrusion of a plasticmaterial, for example from P.V.C. The track is preferably asymmetricalin shape, when viewed in cross section. When using accessory connectorsof similar asymmetrical cross section, electric power of the correctpolarity is supplied to the associated tool. results because accessoryconnector can only be fitted to the track in one way due to theasymmetry. n

The present invention will now be described in more detail by way ofexample with reference to the accompanying drawing which shows a trackin cross section.

The track 10 is an elongate member which is an extrusion of a plasticsmaterial, preferably 'P.V.C. The track 10 has a base 11 from thelongitudinal edges of which sides 12, 13 project substantiallyperpendicularly to the plane of the base 11. It will be seen thereforethat the track 10 is generally of U- shaped cross section. The sides 12and 13 have portions 14 and 15 of increased thickness which extend awayfrom the base part way-along the inner surfaces of the sides. Channels16 and 17 are formed within the thickened portions 14 and 15 and thechannels extend longitudinally along the sides 12, 13 of the track.Housed within the channels l6, 17 are a pair of conductor strips 18, 19made of copper. The conductor strips are made a close fit withinthechannels to prevent movement relative to the channel. Access to theconductor strips 18, 19 is provided by slots 20, 21 which are formed inthe thickened portions 14, 15. As will be seen from the drawing, theslots 20, 21 are inclined towards the base 11 of the track 10. The slots20, 21 allow contacts of accessory electrical connectors (not shown) totouch the conductor strips so that electrical power can be supplied tothe connector strips and withdrawn therefrom as required. The width anddepth of the slots 20, 21 however are such that it is impossible forpersonnel to touch the conductor strips 18, 19 with the fingers. Therisk of receiving shocks is therefore eliminated.

The inner surface of the base 1 1 includes a recess 23 in which afurther conductor strip 24 is located. This further conductor strip 24can be used for example as an earth line. As will be seen from thedrawing, the lateral surfaces 25, 26 of the recess are inclined anddiverge away from the inner surface of the base 11. The furtherconductor strip 24 fitted in the recess 23 is of corresponding shape.The strip 24 is therefore prevented from disengagement with the recess23. lt will be appreciated the strip 24 could be retained in the recess23 in other ways. For example, the strip 24 could be of rectangularcross section, and the recess23 could be provided with lips to preventthe strip 24 from dropping out of the recess 23. Alternatively, thestrip could be riveted or otherwise secured to the base 11. Theconductor strip can be a material such as aluminium.

The sides 12, 13 are each further provided with a flange 26, 27 which,in the embodiment shown, projects in part towards the opposite side. Theflanges 26, 27 form projections or ledges on which accessory electricalconnectors can be slidably mounted. In addition, the flanges 26, 27include extensions 28, 29 which are arranged substantially parallel tothe plane of the sides. Grooves 32, 33 are therefore formed adjacent theend of the sides remote from the base. The grooves allow the track 10 tobe slid into a correspondingly shaped external mounting track 34 whichis secured to a surface such as a ceiling or wall. The external mountingtrack 34 can be secured to the surface by using T-bolts (not shown),which engage the grooves formed by flanges 36. When required, the track10 can be withdrawn from the mounting track with ease. It will beappreciated that the track 10 could be provided with a row of apertures,for example in the base 11. The track 10 could therefore be directlysecured to the surface by screwing or bolting thereto. Thus an externalmounting track would be unnecessary.

The track 10 is asymmetrical about a plane parallel to the sides,through the centre line of the elongate member. In particular, the base11 includes a longitudinal groove 35 located adjacent the side 12. Theinner surface of the base is additionally inclined in a directiontowards the conductor strip mounted in the side 13. Owing to theasymmetrical shape of the track 10, a correspondingly shaped accessoryelectrical connector (not shown) can only be inserted one way round.When the conductor strips 18, 19 are connected to an electrical supply,the correct polarity of the power supplied to an appliance, by way ofsuch a connector, is thus ensured.

We claim:

1. A track for the distribution of electricity, comprising:

an elongate insulating member having a base;

two sides projecting away from the longitudinal edges of said base, eachside having a channel formed therein;

a pair of electrically conducting strips carried by the sides in saidchannels;

said sides having projections on which accessory members can be slidablymounted; and

said sides having longitudinally-extending slots formed therein therebyproviding access to said conducting strips from the central region ofsaid elongate insulting member.

2. A track according to claim 1, wherein the said two sides are groovedat locations remote from said base to position and retain said elongateinsulating member in an external mounting track.

3. A track according to claim 2, in which both said projections and thegrooved portions of said sides are formed by common inwardly projectingflanges carried on the inner surfaces of said sides.

4. A track according to claim 1, in which the longitudinally extendingslots associated with the said channels are defined by inclined surfaceswhich incline away from said sides towards said base of said elongatemember.

5. A track according to claim 1, wherein the said track is asymmetrical,in cross section, about a plane parallel to the 'said two sides.

6. A track according to claim 5, wherein the inner surface of said baseadjacent one of the said sides has a longitudinal groove formed therein,the inner surface of said base being inclined towards the said conductorstrip carried by the other side.

' 7. A track according to claim 1, wherein the inner surface of

